27
Co
58.9332
Kobolt
Engelska: Cobalt
Övergångsmetall
Grupp 9
Period 4
Block d
Kobolt är ett kemiskt grundämne i det periodiska systemet med kemisk beteckningen Co och atomnummer 27 med en atomvikt på 58.9332 u och klassas som övergångsmetall och ingår i grupp 9 (koboltgruppen). Kobolt är fast vid rumstemperatur.
Kobolt i det periodiska systemet
| Tecken | Co |
| Atomnummer | 27 |
| Grupp | 9 (Koboltgruppen) |
| Period | 4 |
| Block | d |
| Ämnesklass | Övergångsmetall |
| Utseende | Hard lustrous gray metal |
| Färg | Grå |
| Antal protoner | 27 p+ |
| Antal neutroner | 32 n0 |
| Antal elektroner | 27 e- |
Från Wikipedia, den fria encyklopedinKobolt är ett hårt, silvergrått, magnetiskt, metalliskt grundämne med kemisk beteckning Co. Kobolt är ferromagnetiskt med en curiepunkt på 1388 K (1115 C).
Fysikaliska egenskaper
| Fas vid STP | Fast |
| Densitet | 8.9 g/cm3 |
| Relativ atommassa | 58.9332 u |
Thermal properties
| Smältpunkt | 1768 K 1494.85 °C 2722.73 °F |
| Kokpunkt | 3200 K 2926.85 °C 5300.33 °F |
| Ångbildningsvärme | 373.3 kJ/mol |
Atomära egenskaper
| Elektronegativitet (Paulingskalan) | 1.88 |
| Elektronaffinitet | 63.898 kJ/mol |
| Oxidationstal | −3, −1, 0, +1, +2, +3, +4, +5 (an amphoteric oxide) |
| Jonisationspotential |
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Elektronkonfiguration för kobolt
Elektronkonfiguration Kortfattad konfiguration | [Ar] 3d7 4s2 | ||||||||||||||||||||||
| Full konfiguration | 1s2 2s2 2p6 3s2 3p6 3d7 4s2 | ||||||||||||||||||||||
Elektronkonfigurationsdiagram |
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| Elektroner per skal | 2, 8, 15, 2 | ||||||||||||||||||||||
| Outer shell electrons | 2 | ||||||||||||||||||||||
| Valence electrons (incl. d) | 9 | ||||||||||||||||||||||
| Valency-elektroner | 2,3 | ||||||||||||||||||||||
| Bohrs atommodell | Figur: Skaldiagram över Kobolt (Co) atom. | ||||||||||||||||||||||
Orbitaldiagram |
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The history of Cobalt
| Upptäckt och första isolation | Georg Brandt (1735) |
Upptäckten av kobolt Cobalt has been used to color glass since the Bronze Age. The word cobalt is derived from the German kobalt, from kobold meaning "goblin", a superstitious term used for the ore of cobalt by miners. The first attempts to smelt those ores for copper or silver failed, yielding simply powder (cobalt(II) oxide) instead. Because the primary ores of cobalt always contain arsenic, smelting the ore oxidized the arsenic into the highly toxic and volatile arsenic oxide, adding to the notoriety of the ore. Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt circa 1735, showing it to be a previously unknown element, distinct from bismuth and other traditional metals. Brandt called it a new "semi-metal". He showed that compounds of cobalt metal were the source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Cobalt became the first metal to be discovered since the pre-historical period. All other known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers. | |
| Original word | kobold |
| Language of origin | German |
| Name source | Mytologi |
| Meaning | “Goblin” |
Naming The name is derived from the German word 'kobald', meaning goblin or evil spirit. It was named by miners in 16th century Saxony who thought they had found deposits of silver but had actually found cobalt arsenide. | |